ADVANTAGES OF DATABASE MANAGEMENT SYSTEM (DBMS)

REDUCTION OF REDUNDANCIES

• Redundancy means duplication (Making the same copy again),Reduction of Redundancy means avoiding duplication of data and reduces the total amount of storage space required.
• It also reduces the extra processing time to search the required data in a large mass of data.
• Another advantage of avoiding duplication is the elimination of the inconsistencies (difficult) in searching the exact data file required.

DATA INDEPENDENCE AND EFFICIENT ACCESS

• Database programs in the database are independent of their storage details.
• The conceptual schema provides physical storage details and external schema provides logical storage details i.e., the conceptual schema provides independence from external schema.It means,physical storage details are independent from logical storage details.
• DBMS strongly provides the efficient access - retrieval of the stored information,including support for very large files,index structures in query optimization.

DATA INTEGRITY

• Data integrity means that the data values entered in the database must be checked to ensure that they fall within a specified range and are of correct format (type).
• For example,the value for the age of an employee must be in the range of 16 nad 55.
• dta Intrgrity also checks that if we are referring any field,then that field must exist.For example, a user is not allowed to transfer funds from a existing savings account to a non-existent savings account.

DATA SECURITY

• Data is of vital importance to an organization and must be confidential.Such confidential data must be secure strongly and may not be accessed by any unauthorized persons.
• DBA should ensure that proper & different access permissions are given to different types of users.
• For example: a manager can access the salary details of employee in his department only.

REDUCED APPLICATION DEVELOPMENT TIME

• Since the DBMS provides several pre-defined functions like concurrency control,crash recovery,high - level query facilities etc., only application - specified code needs to be written by the users.

CONFLICT RESOLUTION

• The DBA should resolve the conflicts among various users to access the same datafiles.
• The DBA chooses the best file structure and access method to get optimal performance for using critical applications.

DATA ADMINISTRATION

• DBMS facilitates maintenance and administration of data by providing a common base for a large collection of data that is shared by several users.
• In addition,the DBA ensures the fine - tuning of data representation,periodic backups,ensures proper permissions of data access,monitoring all jobs,etc.

CONCURRENT ACCESS

• Many users access a single program concurrently (at the same time) as if their programs were running in isolation.
• The DBMS executes the actions of the program in such a way that the concurrent access is permitted but the conflicting operations are not permitted to proceed concurrently.

CRASH RECOVERY

• The DBMS maintains a continuous log (record) of the changes made to the data,so that,if there is any system crash by power failure,it can restore the database to a previously stored consistent state.
• That is the actions of incomplete transactions are undone,so that the database stores only the actions of complete transactions after recovert from a crash.